Click "Start -> Run." Then, type in the Run field: "secpol.msc." That will bring you to Vista's security policy system. Once there, use "Go to: Local Policies > Security Options" and then find "Network Security: LAN Manager" authentication level. Once there, change the Setting from "Send NTLMv2 response only" to "Send LM & NTLM -- use NTLMv2 session security if negotiated."